This application claims the priority of German application 196 17 986.6 filed in Germany on May 4, 1996.
The invention relates to a sweeping machine, with a housing incorporating a refuse collection container, which has at its front area, rotating in opposite directions towards the inside and about forwardly inclined rotatable axles, two circular brooms sweeping across a sweeper plate inside the housing which extends back up to the refuse collection container.
Manually operated sweeping machines of this type (German Patent Document DE 41 01 888 A1) have the merit of being simple in construction and they operate efficiently. They offer considerable advantages, particularly when sweeping up coarse rubbish and leaves.
Manually operated or push-operated sweeping machines are also known which have a cylinder broom, or two arranged one behind the other, extending transversely across the width of the sweeping machine. If two cylinder brooms are provided, the two cylinder brooms are so driven that the first one sweeps away from the front region and the second one sweeps in the opposing direction, whereby the second one hurls the sweepings into a refuse collection container arranged thereafter. With this type of sweeping machine, another known system is to arrange a circular broom on one or both sides in the front region of the housing in front of the cylinder broom or brooms, sweeping inwards so as to carry the rubbish to be picked up to the area which is being swept by the cylinder brooms.
An underlying objective of the invention is to provide a sweeping machine of the type outlined above, which sweeps more efficiently and can be used for all purposes, in particular for sweeping finer refuse.
This objective is achieved according to preferred embodiments of the invention by the fact that a cylinder broom sweeping in the direction towards the front region is arranged behind the circular brooms and the bristles thereof adjoin the sweeper plate and a refuse collection container is arranged on the side facing away from the sweeper plate.
In the sweeping machine of the invention, the circular brooms pick up the coarser refuse in the central area where these collide or where a only short distance is retained between them, and sweep it across the sweeper plate towards the interior of the housing. Finer sweepings, for example fine, dry dust, are swept into the central region and then picked up by the cylinder broom arranged behind. The cylinder broom arranged behind the circular brooms therefore takes control of the rubbish swept by the circular brooms across the sweeper plate towards the inside, accelerating it such that it is thrown upwards and backwards into the refuse collection container. This system therefore also offers the possibility of being able to carry coarse rubbish and leaves, for example, far back into the refuse collection container, which means that a high-volume refuse collection container can be used which can be filled "from the back forwards". The capacity of the refuse collection container is improved as a result.
The design of preferred embodiments of the invention is such that an essentially part cylindrical guide wall is provided for the cylinder broom, the upper end of which adjoins the end of the sweeper plate facing towards the cylinder broom. In conjunction with the bristles of the cylinder broom, this guide wall forms a relatively narrow passage of a few millimeters so that the risk of the dust swept up by the cylinder broom being swirled or blown away is relatively low.
In another aspect of preferred embodiments of the invention, the end of the sweeper plate facing towards the cylinder broom is provided with an upwardly bent end portion, oriented somewhat at a tangent to the external circumference of the bristles of the cylinder broom. By dint of this end portion, the sweepings conveyed by the circular brooms across the sweeper plate do not penetrate the cylinder broom too deeply and can be readily released therefrom.
In yet another aspect of preferred embodiments of the invention, the circular brooms and their bristles extend out beyond the end of the sweeper plate into the region of the bristles of the cylinder broom. Consequently, the cylinder broom fulfills another function, namely that of cleaning the bristles of the circular brooms.
Another aspect of preferred embodiments of the invention is a design configured so that the axial length of the cylinder broom is smaller than the distance between the rotatable axles of the circular brooms, preferably about 30% smaller. On the one hand, a cylinder broom of this type is not as expensive to provide and, on the other, it is perfectly adequate for picking up any refuse, particularly fine, dry dust, left behind between the circular brooms and not yet picked up thereby. In these embodiments, cross-walls are provided in the region of the two end faces of the cylinder broom extending in the longitudinal direction of the housing, each of these being located above a circular broom. The effect of these cross-walls is that the greater proportion of the sweepings moved by the circular brooms reaches the area of the cylinder broom, where they are picked up and accelerated thereby. The cross-walls offer an additional advantage in that, together with the respective external walls of the housing, they form an air passage which conveys air forwards towards the circular brooms which then push it back into the housing. A large proportion of the air is therefore fed back into the housing by means of the circular brooms, so that the risk of dry dust escaping to the exterior or being blown out by the sweeping machine is very greatly reduced.
Another aspect of preferred embodiments of the invention is a design configured so that the bristles of the cylinder broom consist of several tufts of bristles. Between them, the tufts of bristles form pockets, in which the sweepings from the circular brooms are picked up, carried along with a short portion of the circumference and then flung off.
In another aspect of preferred embodiments, the tufts of bristles are so designed that they are respectively formed by sets of at least two portions, inclined with respect to an external contour of the cylinder broom, which meet more or less in the center of the cylinder broom. This arrangement ensures that the bristles of the cylinder broom are well distributed across the circumference of the cylinder broom so that more or less the same number of bristles is always in contact with the floor being swept.
In another aspect of preferred embodiments of the invention, the housing is provided with wheels in the region facing away from the circular brooms, and these provide the driving motion for the cylinder broom. With this system, the broom is driven by the directional movement of the sweeping machine, which means that there is no need to provide a drive motor or similar drive device.